[erlang-questions] blocking vs non-blocking gen_tcp:accept()

[Robin]

Does gen_tcp:accept() block the entire OS thread or just the calling
erlang process?

"One of the shortcomings of the gen_tcp module is that it only exports
interface to a blocking accept call." ->
http://www.trapexit.org/Building_a_Non-blocking_TCP_server_using_OTP_principles

Does the performance gain of non-blocking accept justify the added
complexity (finite state machine etc)?

thanks,

Robin